Method of plating metal articles



R.1.SH0EMAKER.

METHOD 0F PLATING METAL ARTICLES.

APPLICATION FILED MAR. 5,1918.

1,330,399. l v Patented Feb. 10,1920.

novel composition for use in operations of ROBERT JAY SHOEMAKER, 0F MILWAUKEE, WISCONSIN.

METHOD 0F PLATING METAL ARTICLES.

Specication ot Letters Patent.

Patented Feb. 10, 1920.

Application filed Harch 5, 1918. Serial No. 220.419.

To all whom t may concern Be it known that I, ROBERT J. 'SHoEMAKEm a citizen of the United States, residing at Milwaukee, in the county of Milwaukee and f State of Wisconsin, have invented certain new and useful Improvements in Methods of Plating Metal Articles, of which the following is a specification.

My invention relates to the art of plating metal articles, and has for a principal object to provide an improved method Whereby this operation can be performed more expeditiously, economically and effectively than has been possible heretofore.

A further object is to provide. a flux of this character.

The present invention is a development of the method described in the patent to McClintock and Shoemaker, No. 1,195,376, dated August 22, 1916, and in my co-pendving application Serial No. 17 8,7 28, filed J uly The accompanying drawing shows dia# grammatically an apparatus suitable for carrying out my improved method in connection with the plating of sheet metal withv lead Vor other plating metal. The invention, however, is not limited to this treatment of sheet metal, but may be utilized for so treat.- in pipes, boiler flues, or other articles.

eferring to the drawin s, A designates a vat in which the metal s eets are pickled in acid, muriatic acid, for example, before being brought into contact with the plating metal. B is a furnace having a retort C to contain a body D of plating metal', for example, lead, or some of the common alloys of lead. The sheet of metal E is taken from the pickling vat and run between rollers'F, F, arranged so that the acid squeezed from the plate by the rolls will run back into vat A. Gis a frame arranged at the surface of the body of molten lating metal D oonfining a body of flux which floats on-the plating metal. The rest of the s'nu'rface of the body of plating metal is preferably covered with a thin film of the flux I, the urpose of which is toprevent oxidation o 4the molten metal as described in my application Serial No. 178,728, above mentioned. The metal sheet passes through the body of flux on the frame G into the molten plating metal, and is withdrawn from the retort rollers J, J, and deposited on a conveyer or otherwise disposed of'as convenience may dictate; the sheet being preferably guided in its movement through the plating bath by guides L, M. The rollers J", J remove excess of the plating metal and make it certain that the plating metal is laid smoothl and evenly over the entire surface treate This operation is facilitated by throwin powdered ammoniac occasionally en the rol ers to keep them from scaling. a

The flux which I use is composed of three metal chlorids, one of which is the chlorid of' au alkaline metal. I prefer a composition consisting of zinc chlorid, common salt,

and a small percentage of t-in chlorid. The preferred proportions by weight are eighty per cent. zinc chlorid, fifteen per cent.com mon salt (sodium chlorid) and five per cent. tin chlorid. I have found that the use of the tin chlorid as an ingredient of this flux makes theplating metal flow much more readily over the surface of the article being plated than where the flux consists of 'zinc chlorid alone, or of zinc chlorid and common salt. Common salt is used with the zinc chlorid to lower the meltin point of the flux, as'described in my pen ing application above mentioned.

By means of the improvement above described, it is possible to surface metal articles, such as steel or iron sheets, with a platl ing of lead or lead alloy (the term leadf being intended to cover the common alloys of lead) which will permanently adhere to the sheet and'will uniformly cover the entire surface' treated without pin holes, or other imperfections. I prefer to use, as a metal for lead plating, an alloy consisting l substantially of eighty-five per cent. of lead, ten per cent. of antimony and ve per cent. of tin.

I claim: i

1. Av flux for plating operations containing zinc chlorid as a principal ingredient together with tin chlorid. y

2. A flux for platingoperations containing zinc chlorid as a principal ingredient together`with tin chlorid and common salt.

3. vA ilux for latin operations composed of approximatey eig ty per cent. of zinc loo chlorid, five per cent. of tin chlorid and ffy teen per cent. of common salt.

4. Improvement in the art ofplating metal articles which consists in passing thev articlethrough a molten flux consisting of zinc 'chlorid as a rincipal ingredient together with tin ch el'id and common salt,

and thereafter submerging the article in a. bath of molten plating metal.

5. Improvement in the art of plating iron or steel articles with lead which consists in passing the article through a molten flux consisting of zinc chlorid as a principal ingredient together With tin chlorid and common salt, and thereafter submerging the article in a bath of molten plating metal.

6. Improvement in the art of plating iron or steel articles with lead, which consists in passing the article through a molten flux consisting of zinc chlorid as a principal in gredient together with tin chlorid and common salt, Whiehis supernatant on a bath of the plating metal, and thereafter causing the article to be submerged in the plating metal hath. i

7. A fiux for plating operations composed of a mixture of three metallic chlorids', one 20 of which is the ehlorid of an alkaline metal.

ROBERT JAY SHOEMAKER. 

